The 2016 HAB is expected to measure 5.5 on the severity index introduced in 2014. The index runs from a 10, which is equivalent to the bloom observed in 2011, down to zero. The 2015 bloom was rated at 10.5, Lake Erie’s most severe bloom to date, while 2013’s bloom received a final score of 8.7. Any score above 5 is considered to be of concern.

“However, people will know where the bloom is located, so there is no reason not to travel to Lake Erie for boating or other activities,” said Dr. Richard Stumpf, Oceanographer at NCCOS. “You can find a place that’s clear” by using NOAA’s Lake Erie HABs bulletin, Stumpf emphasized, adding that “most of the lake will be fine.”

The NOAA model that generates the forecast relies on phosphorous data from Heidelberg University as well as on input from three other Lake Erie HAB models, all of which are continually refined as scientists learn more about algal blooms. This year, all four models incorporated last year’s extreme bloom and take into account leftover phosphorous and algal cells still present in the lake from 2015 — something Tom Bridgeman of the University of Toledo called a “phosphorous hangover.” Without inclusion of this “hangover” and little to no rain between now and the end of July, the models would predict a severity as small as 3 for this year’s bloom.

Stumpf and Bridgeman both emphasized that this kind of carryover was in large part due to the severity of the 2015 bloom, and that carryover from previous years does not continue indefinitely but likely only impacts the next year’s bloom.

You can view the full forecast as a recording at go.osu.edu/habsinfo. That site also includes HABs information, satellite images of Lake Erie algal blooms and other media and public resources.

In addition to monitoring and forecast efforts, the event included presentations from Dr. Christopher Winslow of Ohio Sea Grant and Dr. Jay Martin of The Ohio State University, who spoke about two sets of collaborative research efforts aimed at harmful algal bloom monitoring and reduction. A grant from Ohio’s Department of Higher Education, along with Ohio State’s Field to Faucet Initiative, supports projects at a number of Ohio universities aimed at addressing HABs in the state.

Representatives from NOAA, The Ohio State University, Heidelberg University, the University of Toledo, the National Wildlife Federation, Bowling Green State University and LimnoTech were also on hand to answer questions related to the forecast and HABs in general. A number of state and federal Ohio congressional districts were also represented at the event, along with Ohio Governor Kasich’s office.

Phosphorus, which is contained in animal manure and many commercial fertilizers, tends to be the nutrient that determines the size of the bloom. Phosphorus usually enters the lake in the form of fertilizer and manure runoff, as well as sewage runoff from treatment plants and combined sewer overflows caused by heavy rains.

Harmful algal blooms in Lake Erie most often consist of Microcystis, a cyanobacterium — more commonly called blue-green algae — that can produce a liver toxin called microcystin. The toxin can be removed from drinking water drawn from the lake, but significantly increases the cost of water treatment. In addition, harmful algal blooms can severely reduce tourism income, as recreational water use is made hazardous by the toxin, or unpleasant by layers of blue-green algae floating on the water’s surface.

Being able to forecast the HAB’s extent allows community officials and tourism managers to prepare for its impacts and adjust seasonal budgets in advance instead of reacting to the event as it happens.

Located on the 6.5-acre Gibraltar Island in Put-in-Bay harbor, Stone Laboratory is The Ohio State University’s Island Campus on Lake Erie and the education and research facility of the Ohio Sea Grant College Program. The Ohio State University’s Ohio Sea Grant College Program is part of NOAA Sea Grant, a network of 33 Sea Grant programs dedicated to the protection and sustainable use of marine and Great Lakes resources. For information on Ohio Sea Grant and Stone Lab, visit ohioseagrant.osu.edu

As Ohio Sea Grant’s science writer, Christina covers research, education and outreach projects in the Great Lakes for a wide range of audiences. She also helps manage online events like the Global Change, Local Impactclimate webinar series.